President Donald J. Trump sent a dangerous signal Saturday when he invited the murderous president of the Philippines to the White House.

In the world of diplomacy, an invitation to the White House is more than a friendly gesture. By welcoming Duterte, Trump implicitly endorsed the Philippines president’s campaign of unlawful extrajudicial killing of thousands of his nation’s citizens. That is unconscionable.

Trump’s latest irresponsible move not only took his own State Department and National Security Council by surprise. It encouraged strong-arm despots around the word and disheartened their admirable opponents in the global fight for human rights.

Under Duterte, Amnesty International estimates, more than 7,000 Filipinos have died — often on the streets, killed by police or vigilante death squads. Duterte publicly sneers at the idea of due process.

Duterte is not only proud of the killings that have taken place during his presidential administration. He has boasted that as mayor of the Philippines city of Davao before he became president, death squads killed 1,700 suspected criminals and, “I used to do it personally.”

Duterte, who before he was elected said he would kill 100,000 “criminals,” claims he is fighting drug crime. But a Human Rights report in March said the many of the victims have simply been poor Filipinos, not drug kingpins.

Is this a man Trump believes deserves a special American honor?

Trump’s “very friendly” conversation with Duterte was just another instance in which he has blithely invited Americans to wonder whether he is putting their interests first, or those of his own businesses. Trump’s company has richly profited from a deal involving a 57-floor tower in Manila emblazoned with his name. In February, Ivanka Trump’s company applied for two clothing trademarks in the Philippines, to add to the three it already has, and in March it applied for yet another.

Trump may think he is strengthening an alliance with the Philippines as a check on North Korea. But last October, Duterte indicated he was ready to turn away from the longtime ties between the Philippines and the United States and would welcome support from China and Russia.

In the Philippines, blood and tears flow on the streets day after day as masked killers do their work. Police storm into homes, shooting unarmed people. No one is safe. Trump should condemn that, not invite Duterte to break bread at the White House.